Diaphragm for sound-boxes.



P. RUDERT.

DIAPHRAGM FOR souwo BOXES,

APPLICATION FILED JAN- 7. l9l8.

1,289,007. Patented Dec. 24, 1918.

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PAUL RUDERT, OFTARENTUM, PENNSYLVANIA.

DIAPHRAGM FOR SOUND-BOXES.

Specification of Letters Patent.

Patented Dec. 24, 1918.

Application filed January 7, 1918. Serial No. $0,595.

To all whom it may concern:

Be it known that I, PAUL RUDERT, a citizen of the United States, and a resident of Tarentum, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Diaphragms for Sound-Boxes; and I do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates toimprovements in reproducing diaphragms for talking machines and the method of making the same, and more particularly to the diaphragm used in the sound boxes.

This diaphragm consists of a more or less porous material impregnated, permeated and surfaced with a composition of materials of a suitable character to provide 'a hard yet flexible finished article, and such diaphragm will be exceedingly compact and tough, although thin, will be provided with a roughened surface, and thus greatly aid in the production of a true mellow tone.

As is, well known, it is not possible to obtain the best results with reproducing diaphragms made of mica or metal, since such substances must be made very thin and fragile and are easily destroyed, and the sound boxes rendered useless. Therefore, one-of the primary objects of my invention is to produce a substitute for such diaphragms and which will be far superior than any other diaphragm heretofore constructed, while it will be resilient and resonant, impervious to moisture and unaffected by climatic changes. It will also be capable of giving out clear, loud and distinct tones of great depth and volume, and of evenly distributing the sound waves, While such a diaphragm will quickly and completely recover its stable equilibrium, and will not permit any discordant noises, blasts or scratching sounds, which are so frequent with the ordinary diaphragm.

My novel diaphragm is illustrated in the accompanying drawings:

Figure 1 is a top plan view of a diaphragm constructed in accordance with my invention;

Fig. 2 is. a sectional view on the line 2-2 of Fig. 1, showing the coating on the outer surface of such diaphragm;-

Fig. 3 is an enlarged fragmentary sectional view similar to Fig 2.

As a base material for my diaphragm I use a flexible paper, having a roughened surface, and such paper is of an absorbent quality, but other fibrous materials or fabric which are sufliciently absorbent to take up an adequate amount of filling material or materials may be employed; although I find that a paper base, such as I have described, gives the best results.

In the drawings I have designated the paper or base material as 1, and the mottled surface as 2. It is important that such roughened surface be used since such surface serves to direct the sound waves at different angles, and thereby more evenly dis-- tribute the same.

In carrying out my invention, the base material 1 is saturated with a composition of moisture of approximately 16 parts of pulverized resin, 16 parts of volatile liquid, and approximately 2 parts linseed oil. I have found thatby using approximately equal parts of rosin and alcohol with a very low ercentage of oil the best results and a better resonance are obtained than is possible by using a higher percentage of oil. The base material 1 is then dried, then again dipped successively until the desired resonance is acquired, and a suitable coating 3 is formed over the surface. When the desired stiffness is obtained, the paper base is cut to the desired shape and the diaphragm is complete. The effect of the composition of material above described upon the paper is to harden the same to give it the desired resonance, while at the same time-t0 allow is the most desirable volatile liquid to be used, although other liquids, such as gasolens and benzin may readily be used.

While I have described my improved diaphragm as being applicable to sound boxes of talking machines, it will be readily understood-that'the same may be applied to other uses where delicate diaphragms are necessary, and that I do not wish to be limited to sound boxes of talking machines. It will also be readily understood that I do not wish to be limited to the exact composition above described, asvarious changes in most of the component parts of such composition may be made without seriously affecting the finished diaphragm.

Having thus described my invention, what 1 claim is:

1. The method of making diaphragms! for talking machines, consisting in immersing a basic material into a composition composed of approximately 16 arts of rosin, approximately 16 parts of a volatile liquid, and approximately 2 parts of oil, and drying the same.

2. The method of making diaphragms for talking machines, consisting in immersing a porous basic material into a composition composed of approximately 16 parts of rosin, approximately 16 parts of alcohol, and approximately 2 parts of linseed oil, and drying the same.

,3. The method of making diaphragms for talking machines, consisting in immersing a paper base into a compositlon composed of approximately 16 parts of pulverized rosin,

approximately 16 parts of alcohol, and approximately 2 parts of linseed oil, and drying the same, substantially as described.

4. As an article of manufacture a diaphragm for talking machines comprising a paper base having a roughened uneven surface, said paper base being impregnated with a composition of approximately 16 parts of pulverized rosin, approximately 16 parts of alcohol, and approximately 2 parts of vegetable oil, substantially as described.

lln testimony whereof, I, the said PAUL RUDERT, have hereunto set my hand.

lPAUL RUDERT.

Witnesses O. C. CAMP, J12, Emmson HAZLETT. 

